JP2013112511A - Sheet conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet conveying device which appropriately conveys a sheet even if the sheet has a size equal to or less than a card size and is made of a hard material, and also appropriately conveys a sheet such as a paper having a size larger than the card size.SOLUTION: A first lower guide portion 41 and a first upper guide portion 33 which guide conveyance of a sheet are arranged to face each other with an interval therebetween. In addition, both guide portions are formed to face a bottom surface of the sheet and a top surface thereof respectively. In the first upper guide portion 33, a concave portion 78 concaved in a direction separating from the first lower guide portion 41 is formed at one part in a right and left direction perpendicular to a sheet conveying direction. Thereby, a distance between first and second guide portions at a portion facing the concave portion is greater than that at a portion not facing the concave portion.

Description

  The present invention relates to a sheet conveying apparatus for conveying a sheet.

  The image scanner includes a sheet conveying device that conveys a sheet along a conveying path that passes through an image reading unit.

  In order to reduce the size of the apparatus, the conveyance path is often formed in a curved shape. In this case, the sheet conveying apparatus includes a first guide and a second guide that are curved along the conveying path. The first guide and the second guide are provided so as to face one side and the other side of the sheet conveyed on the conveyance path, respectively, across the conveyance path. The sheet is conveyed while being guided along the conveyance path by the first guide and the second guide.

JP 2003-87499 A

  It has been studied to make an image scanner capable of reading a surface image such as an identification card or a credit card.

  Credit cards and the like are made of a hard material such as plastic. Therefore, if the distance between the first guide and the second guide is small, a card-sized sheet made of a hard material cannot pass through the conveyance path. Even if the sheet can pass through the conveyance path, a large force is applied to the sheet from the first guide and / or the second guide, and the sheet is damaged or a bend mark remains on the sheet.

  By expanding the distance between the first guide and the second guide, it is possible to solve the problem relating to the card-sized sheet made of a hard material. However, if the distance between the first guide and the second guide is large, another problem occurs when paper of A4 size or the like is conveyed.

  For example, in order to separate the sheets one by one at the entrance of the conveyance path, a separation piece that contacts the roller and the circumferential surface of the roller is provided. If the distance between the first guide and the second guide is large, when tension is applied to the paper that has passed between the circumferential surface of the roller and the separation piece, the separation piece is separated from the circumferential surface of the roller by the paper. May be lifted in the direction. When the separation piece is separated from the peripheral surface of the roller, the sheet separation performance by the separation piece is lowered, and the sheets are double-fed.

  The object of the present invention is to provide a sheet that can be transported satisfactorily even when the sheet having a size smaller than the card size is made of a hard material, while being able to transport the sheet satisfactorily. It is to provide a transport device.

  In order to achieve the above object, a sheet conveying apparatus according to the present invention includes a first roller for conveying the sheet, with a surface on one side of the sheet contacting a peripheral surface, and a sheet on the one side of the sheet. The sheet is configured to face each other, and is configured to face the first guide part for guiding the conveyance of the sheet with a space from the first guide part and face the other side of the sheet. And a second guide part for guiding the conveyance of the sheet. In the second guide portion, a concave portion recessed in the other side is formed in a part of the width direction orthogonal to the sheet conveying direction. A bottom surface in the recess is convexly curved toward the one side.

  The sheet is conveyed by a frictional force that one surface thereof receives from the peripheral surface of the first roller. The first guide portion and the second guide portion for guiding the conveyance of the sheet are opposed to each other with a space therebetween, and are configured to face the one side surface and the other side surface of the sheet, respectively.

  In the second guide portion, a concave portion that is recessed in a direction away from the first guide portion is formed in a part of the width direction orthogonal to the sheet conveyance direction. Therefore, the space | interval between a 1st guide part and a 2nd guide part becomes larger than the part which does not oppose a recessed part in the part facing a recessed part.

  When a sheet having a card size or less is passed through a relatively large space (a portion facing the recess) between the first guide portion and the recess of the second guide portion, the sheet is made of a hard material. Even so, it is possible to suppress the sheet from coming into contact with the second guide portion with a strong force. As a result, the sheet can be prevented from being conveyed while being largely curved, and the sheet can be conveyed satisfactorily without damaging the sheet or leaving a bend mark on the sheet.

  In addition, since the bottom surface in the recess is convexly curved to the side opposite to the recess in the recess, the sheet can be prevented from being damaged at the bottom surface in the recess.

  A sheet having a size larger than the card size passes through a relatively small space between the first guide portion and the second guide portion. Therefore, when a tension is applied to the sheet, the tension can be received by the second guide portion.

  Thereby, the separation member for contacting the peripheral surface of the first roller upstream of the concave portion in the conveying direction and sandwiching the sheet between the peripheral surface of the first roller and separating the sheets one by one Can be prevented from being lifted from the circumferential surface of the first roller by the tension applied to the sheet. As a result, it is possible to suppress a decrease in sheet separation performance by the separation member, and thus it is possible to convey the sheet satisfactorily without causing double feeding of the sheet.

  Therefore, even when a sheet having a size equal to or smaller than the card size is made of a hard material, a sheet such as paper having a size larger than the card size can be transported well while the sheet can be transported satisfactorily.

  The bottom surface in the recess is preferably curved so that the distance from the first guide portion becomes narrower toward the downstream side in the sheet conveyance direction.

  Thereby, when the front end of the sheet moves beyond the portion facing the recess and the portion not facing the recess, the surface on the other side of the sheet may come into contact with the bottom surface in the recess as the sheet is conveyed. . In this case, the posture on the front end side of the contact portion of the sheet changes to a posture along the space between the first guide portion and the portion of the second guide portion beyond the recess. Therefore, the sheet can be transported satisfactorily between the first guide portion and the portion of the second guide portion beyond the recess.

  A second roller that conveys the sheet sent by the first roller in the conveyance direction may be provided downstream of the first roller in the conveyance direction. In this case, it is preferable that a space is provided between the recess and the second roller.

  Thereby, it can suppress that a sheet | seat contacts the bottom face in a recessed part strongly, and can suppress the curvature of a sheet | seat.

  If the corner in the width direction formed by the portion outside the recess and the recess in the second guide portion is sharp, the sharp corner may come into contact with a sheet having a size larger than the card size, and the sheet may be bent along the corner. There is.

  Therefore, it is preferable that the corner in the width direction formed by the portion outside the recess and the recess in the second guide portion is chamfered.

  The first guide part is preferably convexly curved on one side.

  Thereby, it can suppress that the space | interval of a 1st guide part and a 2nd guide part becomes narrow locally, and can convey a sheet | seat more favorably.

  According to the present invention, when a sheet having a size equal to or smaller than the card size is made of a hard material, the sheet can be transported satisfactorily without causing scratches or bending marks on the sheet, and the size larger than the card size. Sheets such as paper can also be transported satisfactorily.

FIG. 1 is an external perspective view of an image scanner 1 according to an embodiment of the present invention, and shows a state when the image scanner 1 is not used. FIG. 2 is an external perspective view of the image scanner 1 and shows a state when the image scanner 1 is used. FIG. 3 is a sectional view of the image scanner 1. FIG. 4 is a cross-sectional view of the vicinity of the first upper guide portion 33 and the first lower guide portion 41 of the image scanner 1. FIG. 5 is a perspective view of the vicinity of the first upper guide portion 33. FIG. 6 is a perspective view of the lower unit 6 of the image scanner 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Appearance structure of image scanner>

  As shown in FIG. 1, the image scanner 1 includes a scanner body 2, a supply tray 3, and a discharge tray 4.

  The scanner body 2 includes an upper unit 5 and a lower unit 6. A sheet discharge port 7 is formed across the upper unit 5 and the lower unit 6 on the front surface of the scanner body 2.

  Note that the front and rear, the left and right, and the top and bottom are defined when the image scanner 1 is viewed from the front side with the image scanner 1 placed on a plane. In each drawing after FIG. 1, in order to facilitate understanding of the drawing, the prescribed direction is indicated by an arrow as necessary.

  The upper unit 5 is coupled to the lower unit 6 so as to be swingable about an axis extending in the left-right direction along the front upper edge of the lower unit 6. Then, the upper unit 5 can be displaced by swinging into a normal posture inclined downward, that is, a posture shown in FIG. 2, and a maintenance posture (not shown) in which the rear end portion is lifted upward from the normal posture. is there. In a state in which the upper unit 5 is in the maintenance posture, the space between the upper unit 5 and the lower unit 6 is opened, and sheet jam processing and maintenance can be performed.

  As shown in FIG. 2, an operation display unit 8 is provided on the upper surface of the upper unit 5. A plurality of operation buttons 9 and a pilot lamp 10 are arranged on the operation display unit 8.

  The lower unit 6 includes side panels 11 each having a trapezoidal shape in side view at the left end and the right end. The pair of side panels 11 form the left and right side surfaces of the image scanner 1. In a state where the upper unit 5 is in the normal posture, the pair of side panels 11 sandwich the upper unit 5 from the left and right, and the left and right side surfaces of the upper unit 5 are covered. In this state, the upper surface of the upper unit 5 is disposed in substantially the same plane as the upper edge of each side panel 11.

  At the upper rear end portion of the lower unit 6, the upper surface of the center portion 12C in the left-right direction is inclined forward and downward. On the center portion 12C, a substantially rectangular plate-shaped main body side guide member 13 is fixedly disposed at the center in the left-right direction.

  The left end portion 12L on the left side and the right end portion 12R on the right side of the center portion 12C protrude upward from the center portion 12C and have a substantially rectangular parallelepiped shape. In a state where the upper unit 5 is in the normal posture, the upper surfaces of the left end portion 12L and the right end portion 12R are substantially flush with the upper surface of the upper unit 5. On the right side surface of the left end portion 12L and the left end surface of the right end portion 12R, there are formed tray support shafts (not shown) extending inward in the left-right direction on the same straight line extending in the left-right direction.

  The supply tray 3 is supported by two tray support shafts so as to be swingable about the tray support shaft. The supply tray 3 is swung to oppose the upper surface of the scanner main body 2 from above, that is, the posture shown in FIG. 1 and the inclination angle of the central portion 12C of the rear upper end of the lower unit 6 is substantially the same. Thus, it can be displaced to a use posture extending from the rear upper end of the scanner body 2 to the rear upper side, that is, the posture shown in FIG. The supply tray 3 is formed in a plate shape that is substantially the same shape as the planar shape of the scanner body 2. Therefore, the upper surface of the scanner main body 2 is covered with the supply tray 3 while the supply tray 3 is in the storage posture.

  A substantially rectangular plate-shaped tray-side guide member 14 is provided on the inner surface of the supply tray 3, that is, the surface facing the front upper side in the use posture. The tray side guide member 14 is fixedly disposed at the front end of the supply tray 3 and behind the main body side guide member 13 in a state where the supply tray 3 is in a use posture.

  In a state where the supply tray 3 is in a use posture, a substantially rectangular sheet supply port 15 extending in the left-right direction is opened in front of the central portion 12C of the rear upper end portion of the lower unit 6.

  In a state where the supply tray 3 is in a use posture, a pair of left and right sheet width guide members 16 are formed across the central portion 12C of the rear upper end of the lower unit 6 and the supply tray 3.

  Each sheet width guide member 16 is divided into a main body side guide member 17 and a tray side guide member 18.

  The main body side guide member 17 integrally includes a placement portion 19 and a width restriction portion 20. The placement portion 19 is disposed along the upper surface of the central portion 12C. The mounting portion 19 has a substantially rectangular plate shape. The placement portion 19 is formed in substantially the same shape as the main body side guide member 13. The width restricting portion 20 rises perpendicularly to the placement portion 19 from the outer edge in the left-right direction of the placement portion 19.

  Note that the concept of “orthogonal” includes not only the intersection at 90 ° but also the case of intersecting at an angle including a slight error at 90 °.

  The tray side guide member 18 integrally includes a placement portion 21 and a width restriction portion 22. The placement portion 21 is disposed along the upper surface of the central portion 12C. The mounting portion 21 has a substantially rectangular plate shape. The placement portion 21 is formed in substantially the same shape as the tray side guide member 14. The width restricting portion 22 rises perpendicularly to the placement portion 21 from the outer edge of the placement portion 21 in the left-right direction.

  A connecting shaft 23 extending in the left-right direction protrudes from the rear end portion of the width regulating portion 20 of the main body side guide member 17. The axis of the connecting shaft 23 coincides with the axis of the tray support shaft that is the swing fulcrum of the supply tray 3. The width restricting portion 22 of the tray side guide member 18 is formed with a portion overlapping the rear end portion of the width restricting portion 20 of the main body side guide member 17 in the left-right direction. The tip of the connecting shaft 23 is inserted through this overlapping portion. Accordingly, the tray side guide member 18 swings about the connecting shaft 23 as the supply tray 3 swings. The main body side guide member 17 and the tray side guide member 18 are arranged in the front-rear direction in a state where the supply tray 3 is in the use posture, and the width regulating portions 20 and 22 are formed in a rib shape extending in the front-rear direction.

  The pair of sheet width guide members 16 are provided so as to be able to approach / separate with the same movement amount with respect to the center between them as a center reference.

  In a state in which the pair of sheet width guide members 16 are closest to each other, the distance between the left and right width restricting portions 20 and 22 is the minimum width that is substantially the same as the length of the short side of the Western business card size. Then, between the pair of sheet width guide members 16, the Western side business card size sheet straddles on the main body side guide member 13, the tray side guide member 14, and the placement portions 19 and 21 of the sheet width guide member 16. Can be placed.

  In addition, in a state where the pair of sheet width guide members 16 are most separated from each other, the distance between the left and right width restricting portions 20 and 22 becomes the maximum width that is substantially the same as the length of the short side of the legal size paper. And between the pair of sheet width guide members 16, the main body side guide member 13, the tray side guide member 14 and the sheet width guide member 16 are placed on the placement portions 19 and 21 of the legal size sheet. The front end, that is, the front end can be placed.

  For a sheet having a size larger than the Western business card size and smaller than the legal size, the pair of sheet width guide members 16 are moved so that the distance between the left and right width restricting portions 20 and 22 is the width in the left and right direction of the sheet. , The main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16 can be placed on the placement portions 19 and 21.

  Thus, the sheet is placed on the rear upper end of the lower unit 6 of the scanner body 2 and the supply tray 3 in the center between the pair of sheet width guide members 16, that is, in the left-right direction of the sheet supply port 15. Set to match the center.

  The discharge tray 4 is formed in a substantially rectangular plate shape. The discharge tray 4 is stored in the lowermost part of the scanner main body 2 (lower unit 6), that is, the state shown in FIG. 1, and the state where the discharge tray 4 is pulled out from the sheet discharge port 7 to the front of the scanner main body 2, ie, FIG. It can be displaced in the state shown in FIG. In a state where the discharge tray 4 is stored in the lowermost part of the scanner main body 2, the front surface 24 of the discharge tray 4 is substantially flush with the front surface 25 of the scanner main body 2 as shown in FIG. 1. On the other hand, when the discharge tray 4 is pulled out to the front of the scanner body 2, the upper surface 26 of the discharge tray 4 is opened upward as a sheet receiving surface as shown in FIG.

In addition, an auxiliary plate 27 is provided on the upper surface 26 of the discharge tray 4 so as to be swingable about an axis along the front edge of the discharge tray 4. The auxiliary plate 27 can be displaced by swinging into a posture lying down with respect to the upper surface 26 and a posture extending forward and upward from the front end portion of the upper surface 26 in a state where the discharge tray 4 is pulled out in front of the scanner body 2. It is.
<Internal configuration of image scanner>

  The upper unit 5 and the lower unit 6 include an upper frame 31 and a lower frame 32, respectively, as shown in FIG. A sheet supply port 15 is formed by the rear edge of the upper frame 31 and the rear edge of the lower frame 32.

  In the upper frame 31, a first upper guide portion 33, an upper CIS holding portion 34, and a final guide portion 35 are successively formed in this order from the rear side.

  The surface facing the lower frame 32 of the first upper guide portion 33 as an example of the second guide portion, that is, the lower surface is a guide surface 36 that guides sheet conveyance. The guide surface 36 extends with a relatively steep slope in the front and lower direction, is curved so as to protrude rearward and downward in the middle, and extends with a relatively gentle slope in the front and lower direction. .

  The upper CIS holding portion 34 is formed as a substantially rectangular recess that is recessed forward and upward. An upper CIS unit 37 is fitted into the upper CIS holding portion 34. The upper CIS unit 37 includes a contact glass 38. The upper CIS unit 37 is provided with the contact glass 38 facing the lower frame 32 side. A coil spring 39 is interposed between the bottom surface of the upper CIS holding portion 34 and the upper CIS unit 37. Thereby, when the thickness of the sheet is large, the upper CIS unit 37 moves according to the thickness, and the sheet is conveyed while being in good contact with the contact glass 38.

  The final guide portion 35 extends forward and downward at substantially the same inclination angle as the front end portion of the guide surface 36.

  In the lower frame 32, a guide portion 40, a first lower guide portion 41, and a lower CIS holding portion 42 are continuously formed in this order from the rear side.

  The upper surface of the guide portion 40 has substantially the same inclination angle as the upper surfaces of the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16, which are placement surfaces on which sheets are placed. And formed in a substantially flat surface inclined forward and downward.

  The surface facing the upper frame 31 of the first lower guide portion 41 as an example of the first guide portion, that is, the upper surface is a guide surface 43 that guides the conveyance of the sheet. A space is provided between the guide surface 43 and the guide surface 36 of the first upper guide portion 33. The guide surface 43 is curved so as to protrude rearward and downward corresponding to the curvature of the guide surface 36, and extends forward and downward in parallel with the front end portion of the guide surface 36.

  Note that the concept of “parallel” includes a case where one side is slightly inclined with respect to the other side and a case where one side is very gently curved.

  The lower CIS holding part 42 is formed as a substantially rectangular concave part that is recessed rearward and downward. A lower CIS unit 44 is fitted in the lower CIS holding portion 42. The lower CIS unit 44 includes a contact glass 45. The lower CIS unit 44 is provided with the contact glass 45 facing the upper frame 31 side.

  The lower frame 32 is formed with a supply roller accommodating portion 46 as a concave portion that is recessed rearward and downward across the central portions of the guide portion 40 and the first lower guide portion 41 in the left-right direction.

  A supply roller 51 as an example of a first roller is rotatably accommodated in the supply roller accommodating portion 46. Part of the peripheral surface of the supply roller 51 protrudes forward and upward from the upper surfaces of the guide portion 40 and the first lower guide portion 41. The supply roller 51 rotates counterclockwise when viewed from the right side during sheet conveyance.

  A sheet-like guide 52 is provided so as to straddle the upper surface of the guide portion 40 and the peripheral surface of the supply roller 51 protruding from the upper surface. The sheet-shaped guide 52 is arranged so that the center thereof coincides with the center of the supply roller 51 in the left-right direction in the left-right direction. The sheet-like guide 52 is made of a film. The sheet-shaped guide 52 has a base end fixed to the upper surface of the guide 40 and a free end in contact with the peripheral surface of the supply roller 51.

  As shown in FIGS. 3 and 4, a regulating member 53, a sheet pressing member 54, and a separation piece unit 55 are provided on the front upper side of the supply roller 51. The restriction member 53, the sheet pressing member 54, and the separation piece unit 55 are attached to the upper frame 31.

  The regulating member 53 is disposed on the downstream side in the sheet conveyance direction with respect to the sheet-like guide 52. The regulating member 53 is formed in a substantially triangular shape in a side view pointed toward the supply roller 51. In the cross section shown in FIG. 4, the restricting member 53 has a restricting surface 56 that extends substantially on the same straight line as the radius of the supply roller 51 that is orthogonal to the straight line extending along the upper surface of the guide portion 40.

  The sheet pressing member 54 is made of a leaf spring. The base end portion of the sheet pressing member 54 is attached to the rear end portion of the upper frame 31. The free end portion of the sheet pressing member 54 is in contact with the peripheral surface of the supply roller 51 from the front upper side.

  The separation piece unit 55 includes a separation piece 57 as an example of a separation member made of rubber. The separation piece 57 is disposed on the downstream side in the rotation direction of the supply roller 51 with respect to the regulating member 53. The surface of the separation piece 57 is in elastic contact with the peripheral surface of the supply roller 51 by the urging force of the spring 58.

  As shown in FIG. 3, LF rollers 61 and 62 are respectively provided at the front end portions of the first upper guide portion 33 and the first lower guide portion 41 so as to be rotatable about an axis extending in the left-right direction. . A part of the peripheral surface of the LF roller 61 protrudes rearward and downward from the lower surface of the front end portion of the first upper guide portion 33, that is, the guide surface 36. Further, a part of the peripheral surface of the LF roller 62 as an example of the second roller protrudes from the upper surface of the front end portion of the first lower guide portion 41, that is, from the guide surface 43 to the front upper side. Then, due to the biasing force of the spring 63, the peripheral surface of the LF roller 61 is in elastic contact with the peripheral surface of the LF roller 62 from the front upper side.

Discharge rollers 64 and 65 are respectively provided at the final guide portion 35 of the upper frame 31 and the front end portion of the lower frame 32 so as to be rotatable about an axis extending in the left-right direction. A part of the peripheral surface of the discharge roller 64 protrudes rearward and downward from the lower surface of the final guide portion 35. Further, a part of the peripheral surface of the discharge roller 65 protrudes forward and upward from the upper surface of the front end portion of the lower frame 32. Then, due to the urging force of the spring 66, the peripheral surface of the discharge roller 64 is in elastic contact with the peripheral surface of the discharge roller 65 from the front upper side.
<Reading images with an image scanner>

  The image scanner 1 can selectively read images formed on the upper and lower surfaces of the sheet. Further, the image scanner 1 can read images formed on both sides of the sheet in parallel. Hereinafter, sheet conveyance and image reading will be described in time series.

  The distance between the pair of sheet width guide members 16 is adjusted to the width of the sheet to be read. Thereafter, the sheet to be read is inserted between the pair of sheet width guide members 16 from the rear upper side. As a result, the sheet is placed on the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16. At this time, the front end portion of the sheet slides on the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16. The front end portion of the sheet moves on the guide portion 40 of the lower frame 32 through the sheet supply port 15. Further, the front end portion of the sheet slides on the guide portion 40 toward the supply roller 51.

  When a plurality of sheets are set, the central portion in the left-right direction at the tip of the lowermost sheet moves from the guide unit 40 onto the sheet-like guide 52. The central portion at the leading end of the sheet slides on the sheet-like guide 52 and is guided onto the peripheral surface of the supply roller 51. Then, when the leading end of the lowermost sheet contacts the separation piece unit 55, the lowermost sheet stops due to frictional resistance with the separation piece unit 55. Further, the upper sheet stops when its leading edge abuts against the regulating surface 56 of the regulating member 53. This completes the sheet setting.

  Further, the free end portion of the sheet pressing member 54 is lifted by the entry of the sheet, and the sheet pressing member 54 comes into contact with the upper surface of the sheet. The lowermost sheet is pressed against the peripheral surface of the supply roller 51 by the urging force of the sheet pressing member 54.

  When the supply roller 51 rotates counterclockwise as viewed from the right side, the lowermost sheet moves together with the peripheral surface of the supply roller 51 by the frictional force between the lowermost sheet and the peripheral surface of the supply roller 51. Further, due to the frictional force between the lowermost sheet and the sheet immediately above the uppermost sheet, the uppermost sheet is dragged and moved. When the leading ends of these sheets come into contact with the surface of the separation piece 57, the movement of the upper sheet is restricted by the separation piece 57, and only the lowermost sheet is the peripheral surface of the separation piece 57 and the supply roller 51. And pass through the nip part.

  The sheet that has passed through the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51 passes through the conveyance path sandwiched between the guide surface 36 of the first upper guide portion 33 and the guide surface 43 of the first lower guide portion 41. It is conveyed while being guided by 36, 42.

  When the leading edge of the sheet comes into contact with the nip portion of the LF rollers 61 and 62, the leading edge of the sheet is drawn into the nip portion by the rotation of the LF rollers 61 and 62. Then, the peripheral surfaces of the LF rollers 61 and 62 come into contact with the upper and lower surfaces of the sheet, respectively, and a conveying force is applied to the sheet from the peripheral surfaces of the LF rollers 61 and 62. Thereby, the conveyance of the sheet is continued.

  Thereafter, as the conveyance of the sheet proceeds, the upper and lower surfaces of the sheet face the contact glass 38 of the upper CIS unit 37 and the contact glass 45 of the lower CIS unit 44, respectively. And in the light emission position of the contact glass 38 and 45, light is irradiated to the upper surface and lower surface of a sheet | seat. Reflected light on the upper and lower surfaces of the sheet is received by the image sensors incorporated in the upper CIS unit 37 and the lower CIS unit 44, respectively, thereby reading the images formed on the upper and lower surfaces of the sheet.

When the leading edge of the sheet comes into contact with the nip portion of the discharge rollers 64 and 65, the leading edge of the sheet is drawn into the nip portion by the rotation of the discharge rollers 64 and 65. The peripheral surfaces of the discharge rollers 64 and 65 are in contact with the upper and lower surfaces of the sheet, respectively, and a conveying force is applied to the sheet from the peripheral surfaces of the discharge rollers 64 and 65. Thereby, the conveyance of the sheet is continued. When the trailing edge of the sheet is separated from the discharge rollers 64 and 65, the sheet is discharged to the upper surface 26 of the discharge tray 4.
<Details of the first upper guide section>

  As shown in FIG. 4, the guide surface 36 of the first upper guide portion 33 is continuous with the curved portion 71 that is curved so as to protrude rearward and downward as a whole, and is continuous with the curved portion 71, and has a gentle slope and a front lower portion. And an inclined portion 72 extending in an inclined manner.

  A central portion in the left-right direction of the bending portion 71 is a card guide portion 73. In the guide surface 36, the left and right side portions of the card guide portion 73 are general guide portions 74.

  The card guide part 73 has a width that is slightly larger than the length of the short side of the credit card in the left-right direction. The card guide portion 73 is formed of a curved surface that curves so as to protrude rearward and downward with a small curvature (a large curvature radius).

  The general guide portion 74 has a steeply inclined portion 75, a curved portion 76, and a gently inclined portion 77. The steeply inclined portion 75 extends with a steeper slope than the inclined portion 72 in the forward and downward direction. The curved portion 76 is continuous to the steeply inclined portion 75 and curved so as to protrude rearward and downward with a larger curvature (smaller radius of curvature) than the card guide portion 73. The gentle inclined portion 77 is continuous with the curved portion 76 and extends forward and downward with the same gradient as the inclined portion 72.

  Since the curvature of the card guide portion 73 is smaller than the curvature of the curved portion 76 of the general guide portion 74, the guide surface 36 is formed with a concave portion 78 recessed forward and upward as shown in FIG. The portion 73 forms the bottom surface of the recess 78.

A large step is formed between the card guide portion 73 and the curved portion 76 of the general guide portion 74, and the corner portion 79 formed by the concave portion 78 and the curved portion 76 is greatly rounded so that the step is eliminated. ing.
<Details of the first lower guide>

  As shown in FIGS. 4 and 6, the guide surface 43 of the first lower guide portion 41 has a curved portion 81 and an inclined portion 82 in order from the upstream side in the sheet conveying direction. The bending portion 81 faces the bending portion 71 of the first upper guide portion 33 from the lower rear side. The inclined portion 82 is continuous with the curved portion 81 and extends forward and downward in parallel with the inclined portion 72 of the first upper guide portion 33.

  As shown in FIG. 4, the bending portion 81 is curved so as to protrude rearward and downward with a smaller curvature than the card guide portion 73 of the first upper guide portion 33. Further, the center of curvature of the curved portion 81 is set at substantially the same position as the center of curvature of the card guide portion 73. Thereby, the space | interval between the card | curd guide part 73 and the curved part 81 becomes narrow toward the downstream of the conveyance direction of a sheet | seat.

Further, since the card guide portion 73 is recessed forward and upward with respect to the general guide portion 74, the interval between the card guide portion 73 and the bending portion 81 is larger than the interval between the general guide portion 74 and the bending portion 81. Is also getting bigger.
<Passing of the sheet between the first upper guide portion and the first lower guide portion>

  The sheet that has passed through the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51 passes between the guide surface 36 of the first upper guide portion 33 and the guide surface 43 of the first lower guide portion 41.

  The leading edge of the credit card size, that is, a sheet larger than the so-called card size, passes through the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51, and then suddenly the general guide portion 74 of the first upper guide portion 33. There is a case where it comes into contact with the inclined portion 75. In this case, the leading edge of the sheet advances while drawing a locus along the curved portion 76 of the general guide portion 74. Thereby, the gradient in the traveling direction of the leading edge of the sheet is increased. When the conveyance of the sheet further progresses, the leading edge of the sheet may come into contact with the curved portion 81 of the guide surface 43 and move while drawing a locus along the curved portion 71. In this case, the traveling direction of the leading edge of the sheet coincides with the gradients of the inclined portion 72 of the guide surface 36 and the inclined portion 82 of the guide surface 43. Thereafter, the leading edge of the sheet moves from the curved portion 81 onto the inclined portion 82 and proceeds while drawing a trajectory along the inclined portion 82.

On the other hand, for example, when the sheet size is equal to or smaller than the card size and the sheet is made of a hard material, the sheet generally passes through the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51, 1 Abuts on the curved portion 81 of the guide surface 43 of the lower guide portion 41. At this time, there is a gap between the sheet and the card guide portion 73 of the first upper guide portion 33. Thereafter, the leading edge of the sheet advances while drawing a locus along the curved portion 81. Along with the movement of the leading edge of the sheet, the sheet gently curves so as to protrude rearward and downward between the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51 and the bending portion 81. And since the space | interval between the card | curd guide part 73 and the curved part 81 is narrower in the downstream of the conveyance direction of a sheet | seat, if conveyance of a sheet | seat further advances, the upper surface of a sheet will contact the card | curd guide part 73, The posture on the front end side of the contact portion of the sheet is a posture along the inclined portion 82 of the guide surface 43. Therefore, the sheet is favorably conveyed between the inclined portion 72 of the guide surface 36 and the inclined portion 82 of the guide surface 43.
<Effect>

  As described above, the sheet is conveyed by the frictional force that the lower surface receives from the peripheral surface of the supply roller 51. The first lower guide portion 41 and the first upper guide portion 33 for guiding the conveyance of the sheet are configured to face each other with a space therebetween and to face the lower surface and the upper surface of the sheet, respectively.

  The first upper guide portion 33 is formed with a recess 78 that is recessed in a direction away from the first lower guide portion 41 in a part of the left-right direction orthogonal to the sheet conveyance direction. Therefore, the distance between the first lower guide portion 41 and the first upper guide portion 33 is larger at the portion facing the recess 78 than at the portion not facing the recess 78.

  Then, a sheet having a card size or less is passed through a relatively large space (a portion facing the recess 78) between the first lower guide portion 41 and the recess 78 of the first upper guide portion 33. Thereby, even if it is a case where a sheet | seat consists of hard materials, it can suppress that a sheet | seat contacts with the 1st upper guide part 33 with a strong force. As a result, the sheet can be prevented from being conveyed while being largely curved, and the sheet can be conveyed satisfactorily without damaging the sheet or leaving a bend mark on the sheet.

  Further, the card guide portion 73 is convexly curved toward the curved portion 81 side of the guide surface 43 of the first lower guide portion 41 and is not bent. Therefore, since the card guide part 73 does not have a corner portion in the cross section, the card guide part 73 can suppress the sheet from being damaged.

  A sheet having a size larger than the card size passes through a relatively small space between the first lower guide portion 41 and the first upper guide portion 33. Therefore, when tension is applied to the sheet, the first upper guide portion 33 can receive the tension.

  Thereby, it is possible to suppress the separation piece 57 from being lifted from the peripheral surface of the supply roller 51 by the tension applied to the sheet. As a result, since the sheet separation performance is not deteriorated by the separation piece 57, the sheet can be conveyed satisfactorily without causing double feeding of the sheet.

  Therefore, even when a sheet having a size equal to or smaller than the card size is made of a hard material, a sheet such as paper having a size larger than the card size can be transported well while the sheet can be transported satisfactorily.

  An LF roller 62 is provided on the downstream side of the supply roller 51 in the conveyance direction, and conveys the sheet in the conveyance direction at a distance from the recess 78.

  When the sheet is made of a hard material, when the sheet enters between the LF rollers 61 and 62, the portion of the sheet on the downstream side in the transport direction from the LF rollers 61 and 62 connects between the rotation axes of the LF rollers 61 and 62. The posture is almost perpendicular to the straight line.

  Therefore, when the LF roller 62 is provided at a position close to the concave portion 78, the sheet has a shape between the card guide portion 73 and the bent portion 81 immediately after passing between the card guide portion 73 and the bent portion 81. Is changed to a posture that is substantially perpendicular to a straight line connecting the rotation axes of the LF rollers 61 and 62. Therefore, the sheet is greatly deformed.

  Since the gap is provided between the concave portion 78 and the LF roller 62 in the conveyance direction, the posture of the sheet is greatly changed immediately after the sheet passes between the card guide portion 73 and the bent portion 81. This can be suppressed. Therefore, it can suppress that a sheet changes greatly.

  In addition, since the corner portion 79 formed by the concave portion 78 and the curved portion 76 is rounded, it is possible to prevent the sheet from being folded along the corner portion 79.

In addition, since the first lower guide portion 41 is convexly curved rearward and downward, there is no portion where the distance between the first lower guide portion 41 and the first upper guide portion 33 is locally narrow. As a result, the sheet can be conveyed more satisfactorily.
<Modification>

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-described embodiment, the image scanner 1 is taken up. However, in addition to the image scanner 1, the sheet conveying apparatus according to the present invention has a mechanism for conveying a sheet, such as an image forming apparatus represented by a printer or a copying machine. It can be widely applied to devices that need it.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

33 First upper guide portion 41 First lower guide portion 51 Supply roller 57 Separating piece 62 LF roller 73 Card guide portion 78 Recessed portion 79 Corner portion

Claims (6)

A surface on one side of the sheet is in contact with the peripheral surface, and a first roller for conveying the sheet;
A first guide portion configured to guide the conveyance of the sheet; and configured to face the one side of the sheet;
The second guide portion is configured to face the first guide portion with a gap and to face the other surface of the sheet, and to guide the conveyance of the sheet,
In the second guide portion, a concave portion recessed in the other side is formed in a part of the width direction orthogonal to the sheet conveying direction,
The sheet conveying apparatus, wherein a bottom surface in the recess is convexly curved toward the one side.   2. The sheet conveying apparatus according to claim 1, wherein the bottom surface in the concave portion is curved such that a distance from the first guide portion becomes narrower toward a downstream side in the conveying direction. A second roller provided on the downstream side in the transport direction with respect to the first roller, and transports the sheet sent by the first roller in the transport direction;
The sheet conveying apparatus according to claim 1, wherein a gap is provided between the concave portion and the second roller.   The sheet conveying apparatus according to any one of claims 1 to 3, wherein a corner portion in the width direction formed by a portion outside the concave portion and the concave portion in the second guide portion is chamfered.   The sheet conveying apparatus according to any one of claims 1 to 4, wherein the first guide portion is convexly curved toward the one side.   The sheet is provided on the upstream side in the conveyance direction with respect to the recess, contacts the circumferential surface of the first roller, and sandwiches the sheet conveyed by the first roller between the circumferential surface, and the sheet The sheet conveying apparatus according to claim 1, further comprising a separating member for separating the sheets one by one.

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